1. Field of the Invention
The present invention relates to oxygen concentrator systems, and more particularly, to a patient ventilator oxygen concentrator system in which a plenum is used to provide a sufficient flow of oxygen-enriched product under various conditions. The plenum may be selectively bypassed to improve the transient response of the concentrator system. Furthermore, the plenum may be trickle charged when needed so as to maintain the reserve capacity of the plenum.
2. Description of the Related Art
Many medical applications exist that require either oxygen-enriched product or medical grade air. Both are widely used in respiratory care treatments, for example. Furthermore, both oxygen-enriched product and medical grade air are used to power various pneumatically driven medical devices.
Hospitals and other medical care facilities have a need for both oxygen-enriched product and medical grade air. In military hospitals and in hospitals in Europe, for example, these needs may be met by using oxygen concentration systems to provide oxygen-enriched product and by using a filtration system for providing medical grade air. On the other hand, hospitals and other medical care facilities in the United States often use high-pressure gas systems or liquid oxygen to gaseous conversion systems to provide oxygen-enriched product.
Commonly used oxygen concentration systems often employ a pressure swing adsorption (PSA) process to remove nitrogen from a given volume of air to produce oxygen-enriched product. Such a process is disclosed in U.S. Pat. No. 4,948,391 to Noguchi and this patent is incorporated herein by reference in its entirety.
In such oxygen concentration systems, for example, as the plenum pressure is increased, the product flow output, that is, the oxygen-enriched product output, is decreased and the oxygen concentration increased. Accordingly, at low plenum pressures, the oxygen concentration of the oxygen-enriched product output may be insufficient.
It is an object of the present invention to provide an oxygen concentrator system which utilizes at least one oxygen concentrator subsystem and a plenum to provide an oxygen-enriched product output.
It is a further object of the present invention to provide an oxygen concentrator system as above and including a plenum charging system to meter and to control the flow of product between the at least one oxygen concentrator subsystem and the plenum and to allow the flow of oxygen product only from the at least one oxygen concentrator subsystem to the plenum. The plenum is trickle charged when needed to maintain its reserve capacity.
It is another object of the present invention to provide an oxygen concentrator system as above and further including a discharging check valve to selectively allow the plenum reserve capacity to flow out only during a high demand oxygen flow.
It is yet another object of the present invention to provide an oxygen concentrator system as above and further including a plenum bypass valve to make the transient response faster and to avoid overdrawing the at least one oxygen concentrator subsystem so as to keep the oxygen concentration of the oxygen-enriched air above a predetermined minimum value.
These and other objects of the present invention are achieved by an oxygen concentrator system comprising: a system air inlet to receive supply air; at least one system outlet to output oxygen-enriched product; at least one oxygen concentrator subsystem including an input to receive supply air from the system air inlet and an output to output oxygen-enriched product to the at least one system outlet; a plenum and a plenum charging system located between the output of the at least one oxygen concentrator subsystem and the at least one system outlet, the plenum charging system selectively enabling oxygen-enriched product to flow from the at least one oxygen concentrator subsystem to the plenum; and an optional plenum bypass valve to selectively bypass the plenum so as to enable oxygen-enriched air to flow from the at least one oxygen concentrator subsystem to the at least one system outlet.
The foregoing and other objects of the present invention are achieved by a method of increasing oxygen concentration, the method comprising: receiving supply air from a system air inlet at an input of at least one oxygen concentrator subsystem and outputting oxygen-enriched product to at least one system outlet; selectively enabling oxygen-enriched air to flow from the at least one oxygen concentrator subsystem to the plenum; and selectively bypassing the plenum to enable oxygen-enriched product to flow from the at least one oxygen concentrator system to the at least one system outlet.
The foregoing and a better understanding of the present invention will become apparent from the following detailed description of an example embodiment and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the foregoing and following written and illustrated disclosure focuses on disclosing an example embodiment of the invention, it should be clearly understood that the same is by way of illustration and example only and that the invention is not limited thereto. This spirit and scope of the present invention are limited only by the terms of the appended claims.